unit Unit1;

 interface

 uses

   Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,

   Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.Imaging.jpeg,

   Vcl.ExtCtrls;

 type

   TRampArray = array[..] of array[byte] of word;

 type

   TForm1 = class(TForm)

     Button1: TButton;

     Button2: TButton;

     Image1: TImage;

     procedure Button1Click(Sender: TObject);

     procedure FormCreate(Sender: TObject);

     procedure Button2Click(Sender: TObject);

     procedure FormDestroy(Sender: TObject);

   private

     { Private declarations }

   public

     { Public declarations }

   end;

 var

   Form1: TForm1;

   origRampArray: TRampArray;

 implementation

 {$R *.dfm}

 function SetBrightness(wBrightness: word): boolean;

 var

   RampArray: TRampArray;

   I, Value: integer;

   DC: HDC;

 begin

   for I :=  to MAXBYTE do

   begin

     Value := I * (wBrightness + );

     if (Value > MAXWORD) then Value := MAXWORD;

     RampArray[][I] := Value;

     RampArray[][I] := Value;

     RampArray[][I] := Value;

   end;

   DC := GetDC();

   try

     Result := SetDeviceGammaRamp(DC, RampArray);

   finally

     ReleaseDC(, DC);

   end;

 end;

 procedure TForm1.Button1Click(Sender: TObject);

 begin

   SetBrightness();

 end;

 procedure TForm1.Button2Click(Sender: TObject);

 var

   DC: HDC;

 begin

   DC := GetDC();

   try

     SetDeviceGammaRamp(DC, origRampArray);

   finally

     ReleaseDC(, DC);

   end

 end;

 procedure TForm1.FormCreate(Sender: TObject);

 var

   DC: HDC;

 begin

   DC := GetDC();

   try

     GetDeviceGammaRamp(DC, origRampArray);

   finally

     ReleaseDC(, DC);

   end

 end;

 procedure TForm1.FormDestroy(Sender: TObject);

 begin

   Button2Click(Button2);

 end;

 end.